An in-vehicle AC generator mounted in a vehicle such as an automobile and driven by an internal-combustion engine is provided with a rectifier that converts an AC voltage induced across the stator winding thereof into a DC voltage, and a regulator that adjusts a voltage induced across the stator winding thereof. In general, the regulator is provided with a circuit unit having a circuit that adjusts a voltage induced across the stator winding, and a heat sink that makes contact with the surface of the circuit unit and radiates heat generated in the circuit unit; the regulator is mounted in a regulator holding unit. The regulator holding unit, a brush holding unit that holds a brush, and an external terminal holding unit that holds an external terminal for connecting the regulator with an external apparatus are integrally assembled in a regulator assembly. The regulator assembly is mounted at an axis-direction end of the AC generator.
In a conventional in-vehicle AC generator, a regulator holding unit provided in a regulator assembly includes a containing portion for containing a circuit unit of a regulator; three sides of the containing portion are surrounded by a wall member and the rest is opened. The circuit unit of the regulator is contained in the containing portion of the regulator holding unit; three peripheral sides of a heat sink adhered to the circuit unit are adhered to a wall member that surrounds the containing portion. In the containing portion of the regulator holding unit, the contained circuit unit is protected and held by a curable resin that is filled into the containing portion through the opened side (for example, refer to Patent Documents 1 and 2).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-16829
[Patent Document 2] Japanese Patent Application Laid-Open No. 2002-142423